SU1317287A1 - Device for measuring velocity and absorption of ultrasound in liquid - Google Patents

Abstract

The invention relates to non-destructive testing and can be used for ultrasonic monitoring of fluid parameters. The aim of the invention is to improve the measurement accuracy at low frequencies by eliminating diffraction distortion. To measure the speed of ultrasound, the fluid is placed in a spherical electro-acoustic transducer excited by two radio pulses. A sequence of pulses is observed on the oscilloscope screen. Change the pulse frequency f of the pulse generator so that the pulses match. The ultrasound speed C is calculated using the formula, where d is the diameter of the electroacoustic transducer. An electroacoustic transducer is driven by a single pulse to measure the absorption. Measured by oscilloscope pulse amplitude. The absorption coefficients of ultrasound are calculated by the formula a 9 (L about and and where and and are the amplitudes of the pulses. 2 Il.

Description

1 13

The invention relates to non-destructive testing and can be used for ultrasonic monitoring of fluid parameters.

The purpose of the invention is to improve the measurement accuracy at low frequencies by eliminating diffraction distortion.

Fig. 1 shows a block diagram of a device for measuring the speed and absorption of ultrasound in a liquid in Fig. 2, and are timing diagrams of pulses during measurements.

The device contains a series-connected electroacoustic transducer 1, an amplifier 2, a joint scanner 3, a delay line 4, the output of which is connected to the sweep input of the oscilloscope 3, the pulse generator 5 and the frequency counter 6 connected in series connected in series are the first key 7, the first counter 8 with the installed capacitance EE element. 9 OR, trigger 10, the first output of which is connected to the control inputs of the first key 7, serially connected second switch 11, the second counter 12 with an installed capacity, the output of which is connected to the second input of the STI element 9 connected in series a generator 13 of sinusoidal signals and 1 rety key 14, the control input of which is connected to the output of the first key 7, and the output to an electro-acoustic transducer 1, the second output of the trigger 10 is connected to; the control input of the second key 11 ,. and the electroacoustic transducer 1 is made in the form of a sphere made of a piezoelectric material 15 with electrodes 16 on the inner and outer surfaces; intended to be filled with the liquid under study 17.

The device works as follows.

C generator 5 pulses. (Fig. 2a) aa INPUT1L keys 7 and 11 and frequency meter

6the sequence of them is received-: pulses, while the key 11 is closed, and the key 7 is open, the pulses through the key

7 passes to the control input of the key 14 (Fig. 26), the counter S starts counting and, overflowing, passes the signal to the element 9 of the RShI and to the line

 4 zader: LCD (fig, 2c) output sig

7 2

The element 9 SHS throws the trigger 10 so that the key 7 closes, and the key 11 opens, and the counter 12 starts counting pulses until

the overflow, then through the second input of the element 9 OR to the trigger 10 enters, the overflow signal from the counter 12, the trigger 10 is thrown, the key 7 is opened, the key 11 is closed, etc.

To measure the speed of ultrasound in a liquid, we set the capacity of the counter 8 to 2, the signal from the generator 13 of sinusoidal signals goes to the key 14, which is opened by the pulses that pass through the key 7 (fig. 2b) and the radio pulses 18 and -19 (fig. 2d ) Electro-acoustic transducer 1 is excited from the output of key 14. Excitation radio pulses 18 and 19, pulses 20 and 21 that have passed a path equal to the diameter d of the sphere and received by transducer 1, pulses 22 and 23 that have passed through j path 2d, etc. (fig. 2d).

Using the delay line 4, set the driver so that on the screen of the oscilloscope 3 you can observe the pulses starting from the pulse 21. Change the frequency f of the pulse generator 5 pulses (Fig. 2e), combine the pulses 21 and 22 on the oscilloscope screen 3 (Fig. 2c) so that the period T of the passage of these pulses would coincide with the time S of the passage of pulses through the test liquid. The pulse frequency f is measured (Fig. 2d) with a frequency meter 6. The speed from ultrasound is equal to the length d of the path traveled divided by the time taken to travel this path. Since the period T of the pulse following coincides with the time S of the passage of pulses through a liquid, the speed C is calculated by the formula

.

To measure the absorption coefficient og in the liquid, the capacity of the counter 8 is set to 1. In this case, the electroacoustic transducer 1 is excited by one

a radio pulse 18 (Fig. 2d) and, setting the delay by delay line 4 so as to observe 3 pulses 20,22,24 on the screen of the oscilloscope (Fig. 2d), are measured by amplitude oscilloscope 3

and, and Uj pulses 20 and 22, then the absorption coefficient is calculated by the formula

. d

Claims (1)

Invention Formula A device for measuring the speed and absorption of ultrasound in a fluid, containing a series-connected electroacoustic transducer, amplifier and oscilloscope, a delay line whose output is connected to fO the first key, the first counter with the installed capacity, the OR element and the trigger, the first output of which is connected to the control input of the first key, connected to the output of the pulse generator, sequentially connected by the second key, the second counter with the installed capacity, the output of which is connected to the second input element OR, serially connected by a generator of sinusoidal signals and a third key, the control input of which is connected to the output of the first key, and the oscilloscope sweep input, after-output - with an electroacoustic predominantly connected pulse generator and frequency meter, characterized in that, in order to improve the measurement accuracy at low frequencies by eliminating diffraction distortions, it is equipped with series-connected to the output of the pulse generator the first key, the first counter with the installed capacity, the OR element and the trigger, the first output of which is connected to the control input of the first key, connected to the output of the pulse generator, sequentially connected by the second key, the second counter with the installed capacity, the output of which is connected to the second input element OR, serially connected by a generator of sinusoidal signals and a third key, the control input of which is connected to the output of the first key, and the output is with an electroacoustic transducer, the second trigger output is connected to the control input of the second key, and the electroacoustic transducer is designed as a field of piezoelectric material to accommodate a controlled fluid with electrodes on the inner and outer surfaces. W figure 1 yo . 24 e P well r9.W A22 ZM t (pus.Z Editor V.Kovtun Compiled by G. Fedorov Tehred A. Kravchuk Order 2413/36 Circulation 499 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, Projecto st., 4 Proofreader L. Patay